This invention relates to a refrigerating system, and more particularly to an improved construction of a refrigerating system wherein a differential valve operable under a pressure difference between the delivery side of the compressor and the condenser is provided for preventing the reduction in the operating efficiency of the refrigerating system caused at the time of starting the system.
In a case where the operation of a refrigerator comprising a compressor, condenser, evaporator and a capillary tube is once interrupted, the refrigerant in the condenser tends to flow out of the condenser, thus reducing the condenser pressure temporarily and deteriorating the operational efficiency of the refrigerator at the starting time thereof. Furthermore, a comparatively high temperature of the refrigerant thus flowing out of the condenser inevitably raises the temperature of the evaporator, thus activating a thermostat and restarting the compressor prematurely.
Various constructions of the refrigerating system (or cycle) have been proposed for preventing the pressure reduction in the condenser, and thereby improving the operational efficiency of the refrigerating system (or cycle) at the starting time.
For instance, in a conventional construction shown in FIG. 1, an electromagnetic valve 2 and a check valve 4 are provided on the delivery side and the inlet side of the condenser 1, respectively. When the operation of the compressor 3 is interrupted, the electromagnetic valve 2 is closed to stop delivery of the refrigerant from the condenser 1, while the check valve 4 is operated to prevent the refrigerant in the condenser 1 from flowing back into the compressor 3.
In the above described construction of the refrigerating system, however, a considerable amount of electric power is consumed in the electromagnetic valve 2, and therefore the operational efficiency of the refrigerating system could not be improved remarkably.